An embedded cap type carbon fiber spoke and its manufacturing method

Abstract

The present invention discloses an embedded cap - type carbon fiber spoke and its manufacturing method. The spoke includes a spoke body, a nipple, and a cap. The spoke body is formed of carbon fiber. One end of the spoke body is connected to the nipple, and the part of the nipple exposed outside the spoke body is provided with threads. The other end of the spoke body is provided with a cap, and the cap is embedded in the spoke body. The nipple, the embedded cap, and the spoke body are coaxially arranged. In the carbon fiber spoke of the present invention, the outside of the cap connected to the hub is a carbon fiber structure, and no metal parts are exposed, which can further reduce the weight of the carbon spoke; only the threads of the nipple connected to the rim are exposed, and other parts are also covered by carbon fiber, improving the torsional resistance of the nipple end; the sizes of the cap and the nipple are very small, approaching those of the metal spokes on the market.

Description

Technical Field

[0001] The invention discloses an embedded cap head type carbon fiber spoke and a manufacturing method thereof, and belongs to the technical field of bicycle wheel spoke manufacturing according to the International Patent Classification (IPC). Background Art

[0002] In the bicycle system, the spoke is the bridge connecting the wheel rim and the hub. During use, one end of the spoke is connected to the hub with a cap, and the other end is screwed and locked with the spoke cap to connect to the wheel rim.

[0003] Currently, spokes on the market are generally made of stainless steel, titanium, aluminum and other materials, which are quite heavy and are not conducive to the increasingly lightweight demand. There are also spokes on the market that use carbon fiber composite materials. First, the spoke body is made, and then metal parts are bonded at both ends of the spoke to make it have the function of a spoke. However, in order to achieve a certain strength, the metal parts bonded at both ends of the spokes made in this way are relatively large. In order to meet the demand for lighter weight, the relevant technology still needs to be improved. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an embedded cap head type carbon fiber spoke and a manufacturing method thereof, which achieves the effects of high strength and light weight by adopting an embedded structure at the cap head end.

[0005] To achieve the above object, the present invention is achieved through the following technical solutions:

[0006] The invention discloses an embedded cap head type carbon fiber spoke, comprising a spoke body, a thread cap and a cap head. The spoke body is formed of carbon fiber. One end of the spoke body is connected to the thread cap. The portion of the thread cap exposed outside the spoke body is provided with a screw thread. The other end of the spoke body is provided with a cap head, and the cap head is embedded in the spoke body. The thread cap, the embedded cap head and the spoke body are coaxially arranged.

[0007] Furthermore, the spoke body includes a spoke core and carbon fiber prepreg, the cap and the cap head are provided with through mounting holes, the cap and the cap head are respectively sleeved on both ends of the spoke core to form a coaxial structure, and the cap, the cap head and the spoke core are wrapped or coated with carbon fiber prepreg and formed as one piece.

[0008] Furthermore, the spoke inner core is cylindrical, and the outer diameter of the spoke inner core is adapted to the size of the mounting hole of the thread cap and the mounting hole of the cap head.

[0009] Furthermore, an annular boss for fixed sleeve connection is provided on the outer periphery of the portion of the tooth cap covered by the carbon fiber prepreg.

[0010] Furthermore, the tooth cap and the cap head are both metal parts, the cap head is a conical cap head, and the portion of the tooth cap covered by the carbon fiber prepreg is provided with a conical structure. The conical design of the tooth cap and the cap head is used to increase the covering area with the carbon fiber prepreg and prevent the end of the prepreg laminate from being too concentrated.

[0011] The present invention also provides a method for manufacturing an embedded cap head type carbon fiber spoke, comprising the following steps:

[0012] S1. Prepare the caps and cap heads at both ends of the spokes, wherein the centers of the caps and cap heads are axially through holes;

[0013] S2. Prepare the spoke inner core, which is made of carbon fiber material, and the spoke inner core is adapted to the axial through hole of the thread cap and the cap head;

[0014] S3, sleeve the thread cap and the cap head onto the two ends of the spoke inner core so that the thread cap and the cap head are coaxially arranged;

[0015] S4, wrapping the spoke inner core, the tooth cap and the cap head with carbon fiber prepreg to form a semi-finished product, wherein the cap head is completely placed inside the carbon fiber prepreg, and a part of the tooth cap is placed outside the carbon fiber prepreg;

[0016] S5. Place the wound semi-finished product into a molding mold and heat it for molding.

[0017] In step S1, the tooth cap and the cap head are both metal products: the cap head is a conical cap head; the part of the tooth cap covered by the carbon fiber prepreg is provided with a conical structure, the peripheral side of the tooth cap is processed into an annular boss to prevent the tooth cap and the carbon fiber prepreg from detaching when stretched, and the side of the tooth cap placed outside the carbon fiber prepreg is processed with a slot to facilitate installation.

[0018] Furthermore, the taper angle of the cap head is greater than the taper angle of the dental cap.

[0019] In step S2, the spoke core is molded or pultruded into a cylinder. Before step S3, the thread cap, the cap head and the spoke core need to be roughened, and the surface of the spoke core is coated with high-strength and high-temperature resistant bonding glue and connected to the thread cap and the cap head for use.

[0020] In step S5, the mold temperature is controlled at 150-160 degrees Celsius, the heating time is 20-30 minutes, and the cross-sectional shape of the spoke body after molding is circular, elliptical or roughly rhombus-shaped.

[0021] In step S5, after the spoke is formed, the mold is opened and taken out, and then the thread is processed on the exposed part of the thread cap, and the nut is assembled.

[0022] The buried cap head type carbon fiber spoke of the present invention has the following beneficial effects:

[0023] 1. The embedded cap head type carbon fiber spoke of the present invention adopts an embedded structure at the cap head end, so that the cap head is completely placed in the package of the carbon fiber prepreg, which solves the problem in the prior art that the cap head and the carbon fiber are not wrapped and can be separated, thereby improving the safety of riding or racing.

[0024] 2. In the present invention, the cap head and the tooth cap are sleeved on the concentric axis, i.e., the spoke inner core, so as to ensure that the cap head and the tooth cap are coaxially arranged, which is beneficial to improving the strength of the spoke.

[0025] 3. A carbon fiber spoke and its manufacturing method according to the present invention adopt the process of gluing and covering the spoke inner core, the metal cap head and the tooth cap with carbon fiber pre-feed. Especially for the structure of the embedded cap head, the spoke body and the cap head form an integral whole. While increasing the strength of the spoke, the size and weight of the cap head are reduced, making the bicycle wheel more lightweight. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the whole of an embodiment of the present invention.

[0027] Figure 2 It is a sectional view taken along the direction A of an embodiment of the present invention.

[0028] Figure 3 It is an enlarged view at position I of an embodiment of the present invention.

[0029] Figure 4 It is a schematic diagram of the cap head structure of an embodiment of the present invention.

[0030] Figure 5 It is a schematic diagram of the tooth cap of an embodiment of the present invention.

[0031] Figure 6 It is a schematic diagram of the nut of an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The present invention will be further described below with reference to the accompanying drawings:

[0033] Embodiment: Please refer to Figures 1 to 6 , an embedded cap head type carbon fiber spoke, including a spoke body 1, a tooth cap 2 and a cap head 3. The spoke body 1 is formed by carbon fiber. One end of the spoke body 1 is connected to the tooth cap 2, and the part of the tooth cap 2 exposed outside the spoke body is provided with threads. The other end of the spoke body 1 is provided with a cap head 3, and the cap head 3 is embedded in the spoke. The tooth cap 2, the cap head 3 and the spoke body 1 are coaxially arranged.

[0034] In an embodiment of the present invention, as shown in Figure 1 , Figure 4 , Figure 5, the spoke body 1 includes a spoke inner core 11 and a carbon fiber prepreg 12. The cap nut 2 and the cap head 3 are provided with through mounting holes. The cap nut 2 and the cap head 3 are respectively sleeved on both ends of the spoke inner core to form a coaxial structure. The cap nut 2, the cap head 3 and the outer part of the spoke inner core are wound or coated with carbon fiber prepreg and integrally formed. The spoke inner core 11 is cylindrical for convenient production. The outer diameter of the spoke inner core 11 is adapted to the sizes of the mounting holes of the cap nut and the cap head. In order to meet the requirements of lightweight and strength, the outer diameter of the spoke inner core is less than 1.8 mm. An annular boss is fixedly sleeved on the outer periphery of the part of the cap nut 2 covered by the carbon fiber prepreg, aiming to increase the covering area of the carbon fiber prepreg or carbon yarn and form an anti-detachment structure. In the present invention, both the cap nut 2 and the cap head 3 are metal parts. The cap head 3 is a conical cap head. The part of the cap nut 2 covered by the carbon fiber prepreg is provided with a conical structure. The conical designs of the cap nut 2 and the cap head 3 are used to increase the covering area with the carbon fiber prepreg and prevent the ends of the prepreg laminate from being too concentrated.

[0035] The present invention also provides a manufacturing method for an inlaid cap head type carbon fiber spoke, including the following steps:

[0036] S1. Prepare the cap nut 2 and the cap head 3 at both ends of the spoke. Axial through holes are respectively formed in the centers of the cap nut 2 and the cap head 3. In step S1, both the cap nut 2 and the cap head 3 are metal products: the cap head is a conical cap head; the part of the cap nut covered by the carbon fiber prepreg is provided with a conical structure. The circumferential side of the cap nut is processed into an annular boss to prevent the cap nut and the carbon fiber prepreg from detaching during stretching. A clamping groove 21 is processed on the side of the cap nut 2 placed outside the carbon fiber prepreg for convenient installation; as Figure 4 and Figure 5 , the axial length of the cap head 3 is significantly shorter than the length of the cap nut 2, and the conical angle of the cap head is greater than the conical angle of the cap nut. The purpose of the embodiment of the present invention is to reduce the size of the cap head under the condition of protecting the strength of the inlaid cap head.

[0037] S2. Prepare the spoke inner core, which is made of carbon fiber material and is adapted to the axial through holes of the cap nut and the cap head. In step S2, the spoke inner core is formed into a cylinder by die molding or pultrusion molding;

[0038] S3. Sleeve the cap nut 2 and the cap head 3 on both ends of the spoke inner core to make the cap nut and the cap head coaxially arranged;

[0039] S4. Wind and coat the spoke inner core, the cap nut and the cap head with carbon fiber prepreg to form a semi-finished product, wherein the cap head is completely placed inside the carbon fiber prepreg, and a part of the cap nut is placed outside the carbon fiber prepreg;

[0040] S5. Place the semi-finished product wound well into a forming mold for heating and forming; in step S5, the mold temperature is controlled at 150 - 160 degrees Celsius, the heating duration is 20 - 30 minutes, and the cross-sectional shape of the spoke body after forming is circular or oval or generally diamond-shaped; after the spoke is formed, open the mold and take it out, then process threads on the exposed part of the cap nut, and assemble and match with the nut 4, as Figure 6 shown.

[0041] In the manufacturing method of the present invention, before step S3, the cap nut 2, the cap head 3 and the spoke inner core need to be roughened. The surface of the spoke inner core is coated with a high-strength high-temperature resistant bonding adhesive and connected with the cap nut 2 and the cap head 3 for standby.

[0042] An embedded cap head type carbon fiber spoke, comprising a spoke inner core made of carbon fiber, a cap nut 2 capable of being fitted and connected to a rim, a small embedded cap head 3, and a carbon fiber prepreg for winding or coating the spoke inner core, the metal cap nut and the embedded cap head; both the cap nut and the embedded cap head are provided with through mounting holes, and the mounting holes of the cap nut and the embedded cap head are respectively fixedly sleeved on two fixed joints and are adapted to the outer diameter size of the spoke body inner core. The carbon fiber spoke inner core is cylindrical, easy to produce and process, and the diameter is the same as the size of the mounting holes of the cap nut and the cap head. The tapered parts of the spoke inner core and the cap nut are all coated or wound with carbon fiber prepreg, and the embedded cap head is completely wrapped by the carbon fiber prepreg, that is, completely placed inside the yarn sheet, and then placed in a forming mold for heating and curing to form an integrally formed carbon fiber spoke.

[0043] The specific process of an embedded cap head type carbon fiber spoke of the present invention is as follows:

[0044] 1. Make metal parts with hollowed-out middles at both ends of the spoke, namely the cap head 3 and the cap nut 2. The material of the metal parts is some high-strength metal materials such as stainless steel, aluminum alloy, and titanium alloy. The diameter of the hollowed-out middle is less than 2 mm. The cap nut 2 is provided with an annular boss, and there is a straight-line slot on the cap nut, which can be used as a fixing function when tightening the nut later to prevent torsion;

[0045] 2. Prepare a carbon fiber core (i.e., the spoke inner core 11), and the diameter is adapted to the diameter of the above-mentioned hollowed-out hole; the carbon fiber core can be formed by a mold or pultrusion;

[0046] 3. Before use, the metal parts and the carbon fiber core need to be roughened. Pass the carbon fiber core through the holes of the cap head and the cap nut first, and coat the surface of the carbon fiber core with a high-strength high-temperature resistant bonding adhesive, and connect them for standby.

[0047] 4. Wind / coat the carbon fiber core and the metal parts with 0-degree or angled carbon fiber prepreg, and gradually wind from the sloped part of the cap nut until the required thickness for design, and wind the product to be formed;

[0048] 5. Place the wound product on the mold and heat it to form (155 °C for 25 mins). The required spoke shape can be circular / flat / elliptical / rhombus-like cross-sectional shapes according to the actual design requirements. Figure 2 It is a spoke with an elliptical shape.

[0049] 6. After forming, open the mold and take out the product. Threads need to be machined at one end of the cap nut. After completion, it is the final usable product, and it is matched with the assembled nut 4, as Figure 6 shown.

[0050] The characteristics of the carbon fiber spokes of the present invention are as follows:

[0051] 1. The outer part of the cap head 3 connected to the hub is a carbon fiber structure, and no metal parts are exposed, which can further reduce the weight of the carbon spokes.

[0052] 2. Only the threads of the cap nut 2 connected to the rim are exposed, and other parts are also covered with carbon fiber, which improves the anti-torsion performance at the cap nut end.

[0053] 3. The sizes of the cap head and the cap nut are very small, close to those of the metal spokes on the market.

[0054] The above descriptions are only examples of using the technical content of this creation. Any modification and change made by those skilled in this art using this creation fall within the scope of the patent claimed by this creation, and are not limited to those disclosed in the examples.

Claims

1. An embedded cap - type carbon fiber spoke, characterized in that: It includes a spoke body, a cap and a head. The spoke body is formed by carbon fiber. One end of the spoke body is connected to the cap. The part of the cap exposed outside the spoke body is provided with threads. The other end of the spoke body is provided with a head, and the head is buried inside the spoke. The cap, the buried head and the spoke body are coaxially arranged. The spoke body includes a spoke inner core and carbon fiber prepreg. The cap and the head are provided with through mounting holes. The cap and the head are respectively sleeved on both ends of the spoke inner core to form a coaxial structure. The cap, the head and the outer part of the spoke inner core are wound or coated with carbon fiber prepreg and integrally formed. Among them, the head is completely placed inside the carbon fiber prepreg, and a part of the cap is placed outside the carbon fiber prepreg. The outer periphery of the part of the cap covered by the carbon fiber prepreg is provided with a fixedly sleeved annular boss.

2. The embedded cap - type carbon fiber spoke according to claim 1, characterized in that: The spoke inner core is cylindrical, and the outer diameter of the spoke inner core is adapted to the mounting holes of the cap and the head.

3. A buried cap - type carbon fiber spoke according to claim 1 or 2, characterized in that: Both the cap and the head are metal parts. The head is a conical head. The part of the cap covered by the carbon fiber prepreg is provided with a conical structure. The conical designs of the cap and the head are used to increase the covered area with the carbon fiber prepreg and prevent the ends of the prepreg laminate from being too concentrated.

4. A manufacturing method of an embedded cap - type carbon fiber spoke according to any one of claims 1 - 3, characterized in that, It includes the following steps: S1. Prepare the cap and the head at both ends of the spoke. The centers of the cap and the head are respectively provided with axial through holes. S2. Prepare the spoke inner core, which is made of carbon fiber material. The spoke inner core is adapted to the axial through holes of the cap and the head. S3. Sleeve the cap and the head on both ends of the spoke inner core to make the cap and the head coaxially arranged. S4. Wind and coat the spoke inner core, the cap and the head with carbon fiber prepreg to form a semi-finished product. Among them, the head is completely placed inside the carbon fiber prepreg, and a part of the cap is placed outside the carbon fiber prepreg. S5. Place the wound and coated semi-finished product into a molding die and heat it to form.

5. A method for manufacturing an embedded cap - type carbon fiber spoke according to claim 4, characterized in that: In step S1, both the cap and the head are metal products: among them, the head is a conical head; the part of the cap covered by the carbon fiber prepreg is provided with a conical structure. The circumferential side of the cap is processed into an annular boss to prevent the cap and the carbon fiber prepreg from detaching during stretching. The side of the cap placed outside the carbon fiber prepreg is processed with a card slot for convenient installation.

6. The manufacturing method of an embedded cap - type carbon fiber spoke according to claim 5, wherein: The conical angle of the head is greater than the conical angle of the cap.

7. A method for manufacturing an embedded cap head type carbon fiber spoke according to claim 4, characterized in that: In step S2, the spoke inner core is formed into a cylinder by die molding or pultrusion. Before step S3, the cap, the head and the spoke inner core need to be roughened. The surface of the spoke inner core is coated with a high-strength high-temperature resistant bonding adhesive and connected to the cap and the head for standby.

8. A manufacturing method of an embedded cap head type carbon fiber spoke according to claim 4, characterized in that: In step S5, the temperature of the die is controlled at 150 - 160 degrees Celsius, and the heating duration is 20 - 30 minutes. After forming, the cross-sectional shape of the spoke body is circular or oval or generally diamond-shaped; after the spoke is formed, it is taken out of the die, and then threads are processed on the exposed part of the cap and matched with nuts.

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